Iron Deficiency in Perimenopause: A Practical Guide

Why Iron Matters More in Perimenopause

Iron is essential for producing haemoglobin, the protein in red blood cells that carries oxygen around your body. When iron levels are low, your cells receive less oxygen, and the result is often relentless fatigue, poor concentration, and a general sense of running on empty. During perimenopause, many women experience heavier or more unpredictable periods due to hormonal shifts, which increases monthly blood loss and the amount of iron your body needs to replace. At the same time, some women find their appetite or dietary patterns shift, meaning less iron-rich food comes in while more goes out. This combination makes iron deficiency one of the more overlooked contributors to perimenopausal fatigue.

Signs You May Be Low in Iron

The most common symptom is persistent tiredness that does not improve with rest. Other signs include pale skin, shortness of breath during mild exertion, heart palpitations, cold hands and feet, headaches, and difficulty concentrating. Some women notice brittle nails or hair that sheds more than usual. These symptoms can easily be mistaken for perimenopause itself, which is why many cases of iron deficiency go undiagnosed for months. If several of these symptoms apply to you, a simple blood test from your GP can check your ferritin level, which reflects your iron stores, alongside your haemoglobin.

How Heavy Periods Drive Iron Loss

In the years before periods stop entirely, cycles often become erratic. Some months may bring lighter bleeding, while others involve flooding, clotting, or periods that last longer than usual. Each time you lose more blood than normal, your body has to work harder to replenish iron. If you are losing significantly more than average over several cycles, it is very difficult to keep up through diet alone. Tracking your cycle and symptoms over time can help you and your doctor see patterns. The PeriPlan app lets you log symptoms and spot trends across weeks and months, which can be useful information to bring to a GP appointment.

Iron-Rich Foods to Prioritise

There are two types of dietary iron. Haem iron, found in red meat, poultry, and fish, is absorbed more efficiently. Non-haem iron comes from plant sources such as lentils, chickpeas, tofu, spinach, pumpkin seeds, and fortified cereals. If you eat meat, including lean red meat two or three times a week is one of the most efficient ways to maintain iron intake. For plant-based eaters, combining non-haem iron sources with vitamin C at the same meal significantly improves absorption. Adding lemon juice to lentils, or eating bell peppers alongside spinach, are simple ways to put this into practice. Cooking in a cast iron pan also adds small amounts of iron to food.

Nutrients and Habits That Affect Iron Absorption

Calcium and iron compete for absorption, so consuming them together in large amounts reduces how much iron you take in. Drinking tea or coffee with meals is another common culprit, as the tannins bind to iron and block absorption. Ideally, leave a gap of at least an hour between iron-rich meals and caffeinated drinks. On the other hand, vitamin C genuinely improves iron uptake, as does stomach acid, which is why people who take acid-reducing medications sometimes become iron deficient over time. If you take a calcium supplement, taking it at a different time of day from iron-rich meals or iron tablets is a sensible approach.

Should You Take an Iron Supplement

Iron supplements are effective when levels are genuinely low, but they are not without side effects. Constipation and nausea are the most common complaints, and taking iron on an empty stomach worsens these for many people. Lower-dose supplements taken with food or every other day are often better tolerated while still raising ferritin over time. Some forms of iron, including ferrous bisglycinate, are gentler on the digestive system than ferrous sulphate. It is worth getting your ferritin tested before starting supplementation, and rechecking after two to three months to confirm levels are rising. Taking high-dose iron without a confirmed deficiency is not recommended.

When to See a Doctor